The death toll stands at 96 after a powerful earthquake struck southern Mexico last week, according to officials.
And an estimated 2.5 million people are in need of aid.
In Oaxaca, the state most seriously affected by the 8.2-magnitude quake, 76 were killed, Governor Alejandro Murat told a local television station.
Sixteen fatalities were registered in the state of Chiapas and four more in Tabasco.
"In the state of Oaxaca, at least 12,000 homes were damaged, but this number will certainly climb in the coming hours," Murat said.
He added that 1 million residents needed food, water, clothes and help to rebuild homes in the state.
Officials in Chiapas said 1.5 million people were affected by the quake.
"Several thousands of public servants of the Federal Police, the Navy, the Civil Protection … have been sent to the affected area where they are distributing food and blankets. Shelters are being installed ", government spokesman Eduardo Sanchez told a radio station.
President Enrique Pena Nieto on Friday declared three days of national mourning during a visit to Juchitan, the city hardest-hit in Oaxaca.
He met with his Cabinet late Sunday to discuss the situation, according to Sanchez.
"The president ordered them all to be in Chiapas and Oaxaca today to supervise and coordinate the reconstruction work and [provide] assistance to all the people who have been affected," he said.
Pena Nieto will travel Monday to areas in Chiapas and Oaxaca.
Because of the quake and Hurricane Katia that hit Mexico a day later, the foreign ministry said Monday it could no longer send supplies and personnel to the U.S. state of Texas that is dealing with the aftermath of Hurricane Harvey that struck late last month.
"It has been reported to the Texas government and the United States federal government that unfortunately this time it will not be possible to provide the aid originally offered to the victims of Hurricane Harvey in Texas," the ministry said in a statement.
Officials said the quake Friday was even stronger than the 8.2-magnitude tremor that killed more than 10,000 people and destroyed a large part of Mexico City in September 1985.
